Goodwill and Other Intangible Assets - Changes in Carrying Amounts of Goodwill by Segment (Details) $ in Thousands	9 Months Ended
Sep. 30, 2018 USD ($)
Changes in carrying amounts of goodwill
Balance at December 31, 2017	$ 401,758
Changes to goodwill	26,737
Foreign currency translation	(8,144)
Balance at September 30, 2018	420,351
Harsco Metals & Minerals Segment
Changes in carrying amounts of goodwill
Balance at December 31, 2017	381,893
Changes to goodwill	26,737
Foreign currency translation	(8,144)
Balance at September 30, 2018	400,486
Harsco Industrial Segment
Changes in carrying amounts of goodwill
Balance at December 31, 2017	6,839
Changes to goodwill	0
Foreign currency translation	0
Balance at September 30, 2018	6,839
Harsco Rail Segment
Changes in carrying amounts of goodwill
Balance at December 31, 2017	13,026
Changes to goodwill	0
Foreign currency translation	0
Balance at September 30, 2018	$ 13,026

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13770-109266

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=77989000&loc=SL49117168-202975

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- Definition

Amount of foreign currency translation gain (loss) which increases (decreases) an asset representing future economic benefits from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

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- Definition

Amount of increase (decrease), classified as other, of an asset representing the future economic benefits from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

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